The Cordilleras are mountains, a huge system of which occupies the western edge of the continent of North America. They stretched for about 7 thousand km. The Cordilleras are mountains characterized by a wide variety of natural conditions. They are characterized by a number of features, and this determines their uniqueness among the rest of the mountain systems of our planet.
General characteristics of the Cordillera
Where are the mountains of the Cordillera? They are predominantly elongated in the submeridional direction. These mountains are formed within five orotectonic belts of different ages. The Cordilleras have in their composition a significant proportion of highlands (2.5-3 thousand or more meters above sea level). They have active volcanism and high seismicity. The large extent of these mountains from north to south has led to the presence here of many spectra of altitudinal zonality. Cordilleras are mountains formed at the junction between lithospheric plates. The border between them almost coincides with the coastline.
Composition of the Cordillera
The third part of the area of the entire continent is occupied by mountain fold-block system. It has a width of 800-1600 km. It includes mountain plateaus, intermountain basins, ranges, as well as volcanic plateaus and mountains. Young deformations, volcanism, denudations have undergone the Cordillera, which determined their current appearance and disguised many geological structures that appeared earlier. The mountain system is very heterogeneous both in the transverse and longitudinal directions.
More about the structure of the Cordillera
Asymmetrical structure of the surface of the mainland, where the mountains of the Cordillera. They occupy its western part, eastern - low mountains and vast plains. The western part is located at an altitude of about 1700 meters, and the eastern part - 200-300 m. 720 meters is the average height of the continent.
The Cordilleras are mountains that include a number of mountain arcs, which are elongated mainly in the direction from the northwest to the southeast. From Mackenzie, Mt. Brooks, the Rocky Mountains consists of the eastern arc. A discontinuous belt formed from internal plateaus and plateaus is located to the west of these ranges. 1-2 thousand meters is their height. The Cordilleras are mountains that include the following plateaus and plateaus: the Yukon Plateau, the Columbian Plateau and the British Columbia Plateau, the Great Basin, the Colorado Plateau, the plateaus and the volcanic plateau of the Mexican Highlands (its inner part). For the most part, they are an alternation of basins, ridges and table flat surfaces.
The highest mountain
The Cordilleras from the western part are marked by a system of the highest ridges. These are the Aleutian Ridge, the Aleutian Islands, the Alaska Ridge. The latter reaches a height of 6193 meters. This is McKinley, the highest mountain shown in the photo above. The Cordillera is a system that also includes in the western part the Cascade Mountains, the Canadian Coast Range, the Western Sierra Madre and the Sierra Nevada, as well as the Transverse Volcanic Sierra with the Orizaba volcano located here (5700 meters) and others.
Height decreases to the west of them. The Cordilleras are mountains that smoothly merge into the flat part of the mainland. It is occupied in the west by either bays (California, Puget Sound, Cook) or lowlands (California Valley, Willamette River Valley). This coast of the continent is formed by the St. Elijah, Chugach, Kenai, Canadian Island Ranges, and the US Coast Ranges. The chains of the Cordillera to the south of the Mexican highlands bifurcate. One of them deviates to the east, forming the islands of the West Indies and underwater ridges, after which it passes into the Venezuelan Andes. The other half stretches across the Isthmus of Panama and Tehuantepec to the Colombian Andes.
What accounts for the diversity of mountain topography?
It is associated with different ages of land areas, as well as with the history of their development. The mainland did not immediately form in its present form. The mountains of the Cordillera in their present form arose thanks to various processes that took place at different times on the continent.
For the Laurentian Upland marked by the most ancientgeological structures, the relief is characterized by leveling surfaces, the formation of which began at the beginning of the Paleozoic. The wavy surface of the modern upland was determined by the different resistance of rocks to denudation, as well as uneven tectonic movement. The subsidence of the central part of the territory caused a sheet of Quaternary glaciation, due to which the depressions of the modern Hudson Bay were formed. In addition, under its influence, the accumulation of water-glacial and moraine sediments occurred, which formed the type of relief (moraine-hilly).
The Great and Central Plains are of the stratal type. Under the influence of denudation processes in various places, depending on the characteristics of the occurrence of various rocks, cuest ridges (Great Lakes), stepped plateaus (Great Plains), midlands and erosional lowlands (Washita, Ozark) were formed.
The relief of the Cordilleras themselves is very complex. The strip of compression of the earth's crust is crossed by numerous faults, starting from the bottom of the ocean and ending on land. The mountain building process has not been completed yet. This is evidenced by volcanic eruptions (for example, Popocatepetl and Orizaba), as well as strong earthquakes that occur here from time to time.
Mineral resources
As you know, many different minerals can be found where there are mountains. The Cordillera is no exception. There are huge reserves of ores of non-ferrous and ferrous metals. From non-metallic, one can distinguish oil, which is located in intermountaindeflections. Brown coal reserves are found in the Rocky Mountains (their inner basins).
Climate
Characteristics of the climate will continue the description of the mountains. The Cordilleras are in the path of oceanic air masses. Because of this, the influence of the ocean sharply weakens to the east. This climatic feature of the Cordillera is reflected in the soil and vegetation cover, the development of modern glaciation, and altitudinal zonation. The elongation from north to south of the mountain ranges predetermines the differences in temperatures in summer and winter. In winter, it ranges from -24 ° С (in the Alaska region) to +24 ° С (Mexico, south of the country). In summer, the temperature reaches +4 to +20 °С.
Precipitation
The northwest receives the most rainfall. The fact is that this part of the Cordillera is located on the path of the westerly winds blowing from the Pacific Ocean. The amount of precipitation here is approximately 3000 mm. Tropical latitudes are the least humidified, since oceanic air masses do not reach them. The low amount of precipitation is also due to the cold current passing near the coast. The inner plateaus of the Cordillera are also not very wet. The mountains are located within the temperate, subarctic, tropical and subtropical climatic zones.
Rivers and lakes of the Cordillera
A significant part of the western rivers of the continent originates in the Cordillera. Mostly their food is snow and glacial, in the summer there is a flood. These rivers are mountainous, swift. The largest of them are Colorado and Columbia. The lakes of the Cordillera are of glacial or volcanic origin. On the inner plateaus there are saline shallow water bodies. These are the remains of large lakes that existed here for a long time, during the humid climate.
Plant world
The flora of the Cordilleras is very diverse. Coniferous forests with a peculiar appearance are located up to 40 ° N. sh. In terms of species composition, they are very rich. Spruce, cypress, fir, thuja (red cedar) are their typical representatives. The height of coniferous trees reaches 80 meters. Between them there is practically no woody undergrowth. However, a variety of shrubs grow here in abundance. There are many mosses and ferns in the ground cover. In the coniferous forests, when moving south, sugar pine, white fir, and yellow pine begin to come across. The evergreen sequoia appears further south. As dryness increases, south of 42 ° N. sh., thickets of bushes are replaced by forests. They are juniper, heather, and their height usually does not exceed two meters. Here you can sometimes find different types of evergreen oak. The humidity of the climate in the interior of the Cordillera is decreasing. They are characterized by dry forests, as well as areas of s altwort and wormwood deserts. The rainfall-receiving mountain slopes are covered up to a height of 1200 m with evergreen forests.
Animals living in the Cordillera mountains
Where the mountains of the Cordillera are located, you can meet the brown grizzly bear - a large predator of the continent of North America. Baribal bear having a long blackfur, lives in the southwest of this system. It destroys livestock and spoils crops. There are also many lynxes, foxes, wolves. Arthropods, lizards, snakes are often found in the southern regions of the mountains. In addition, the gilatooth lives here - the only legless poisonous lizard. Large animals in places where people live are either destroyed or are extremely rare. Bison and pronghorn (a rare antelope) are only saved through national programs in North America. Only in reserves can one observe today a rich fauna.
